PROJECT SUMMARY/ABSTRACT Globally, transgender (`trans') women have 49 times higher odds of HIV infection compared to other groups and trans women living with HIV (TWH) access HIV care and adhere to medication at significantly lower rates than other at-risk groups. Poor engagement in HIV care for TWH is a result of reduced access to and avoidance of healthcare due to stigma and negative experiences with providers, and occurs in the context of social and economic marginalization that foments unstable employment and housing, familial alienation, limited social support, and substance abuse. Interventions to mitigate these barriers to care are critical to reducing HIV-related disparities and poor health outcomes for this highly vulnerable population, particularly where disparities are most apparent, including Brazil. Peer-based navigation (PN) interventions have demonstrated success in improving engagement in HIV care in low-resource settings. Our research group is currently conducting a PN intervention (`I-Care') in rural South Africa that significantly improved both linkage to care and retention for men and women. While the PN intervention addresses HIV care engagement by providing social support and skills to work with health providers and family, it requires specific adaptation and a conceptual model that addresses the unique needs of TWH identified during formative research and in consultations with Brazilian stakeholders in 2015. We propose to develop and conduct a trans-specific PN intervention in Brazil, tentatively named `TransAmigas', which integrates the I-Care approach with the Model of Gender Affirmation (GA), developed by our research team to specifically address HIV prevention and care among trans women. We will use the ADAPT-ITT methodology to develop TransAmigas, incorporating the GA model in the Brazilian context (Aim 1). We will then conduct a pilot study to test the feasibility and acceptability of TransAmigas in So Paulo, Brazil (Aim 2) by randomizing TWH to the intervention (n=100) or to clinical referral (n=50). During the nine month pilot, we will track both navigator and patient adherence to the program, recruitment needs, cohort retention, and reported satisfaction and preferences for program content through surveys at baseline and nine months. Finally, we will prepare for a multi-site efficacy trial (Aim 3) by extracting clinical data from participants' records at the referral clinic, generating preliminary efficacy data by comparing retention in HIV care and viral load by intervention arm. Clinical data will inform future trial sample size. We will implement this study in Sao Paulo, Brazil, where universal access to care and public support for gender transition care provide an enabling environment for this work to be most effective and where the team has established academic partnerships and a collaboration with the State-run reference and training clinical site (CRT), which includes trans-specific clinical services. If feasible, acceptable, and ultimately proven efficacious, TransAmigas will be the first evidence-based HIV care intervention for TWH globally ? filling a crucial gap in programming.